摘要
【目的】研究棉花秸秆还田配施不同氮肥处理对棉秆腐解及土壤理化性质的影响。【方法】以干旱区典型农业土壤-灰漠土为研究对象,采用随机区组设计,以不添加秸秆与氮肥(CK)为对照,设置无氮(0 kg/hm^(2))、低氮(N_(1):112.5 kg/hm^(2)、N_(2):225 kg/hm^(2))、中氮(N 3:450 kg/hm^(2))、高氮(N 4:750 kg/hm^(2))5种氮处理水平。于2019年10月中旬将棉花秸秆打断为3~5 cm,以中等还田量施入18个小区。在1年的棉秸秆腐解期间,定期测定还田棉秆纤维素、半纤维素、木质素含量,土壤有机碳、全氮含量、pH、电导率。分析随着还田腐解时间的延长,棉秸秆主要成分含量与相应土壤理化性质的演变特征。【结果】添氮处理在腐解前期(第256 d)显著降低了还田棉秆木质素含量,而纤维素、半纤维素则在后期显著降低,木质素在腐解前期对氮肥添加更为敏感;棉秆在腐解前期,所有添氮处理的土壤有机碳含量显著增加,腐解后期降低,低氮处理(N_(1)、N_(2))的有机碳含量最高;各处理间土壤全氮含量差异不显著;氮添加处理显著降低了土壤pH值与盐分;土壤有机碳含量与棉秆的木质素、半纤维含量呈显著负相关关系(P<0.05,P<0.01)。【结论】秸秆还田配施氮肥能加速棉秸秆腐解,而低氮处理(N_(1)、N_(2))在加速秸秆降解的同时,有利于增加土壤有机碳含量,培肥土壤。
【Objective】To investigate the effects of different nitrogen fertilizer treatments on cotton stalk decomposition and soil physical and chemical properties.【Methods】The typical agricultural soil-grey desert soil in arid area was taken as the research object.Five nitrogen treatment levels(0 kg/hm^(2)),low nitrogen(N_(1):112.5 kg/hm^(2),N_(2):225 kg/hm^(2)),medium nitrogen(N 3:450 kg/hm^(2)),and high nitrogen(N 4:750 kg/hm^(2))were set in random block group with no straw addition and nitrogen fertilizer(CK)as the control.In the middle of October,2019,the cotton straw was interrupted for 3-5 cm and put into 18 experimental plots with a medium returning quantity.The contents of cellulose,hemicellulosic,lignin,soil organic carbon,total nitrogen,pH and electrical conductivity of cotton stalk returned to the field were measured regularly during the decay of cotton stalk for one year.The evolvement characteristics of main components content of cotton straw and corresponding physical and chemical properties of soil were analyzed with the extension of decomposition time.【Results】Compared with nitrogen-free treatment,nitrogen-added treatment significantly reduced the lignin content of cotton stalk returned to the field in the early stage of decomposition(day 256),while cellulose and hemicellulose significantly decreased in the later stage,indicating that lignin was more sensitive to nitrogen fertilizer addition in the early stage of decomposition;In the early stage of cotton stalk decay,the organic carbon content of all soil treated with nitrogen increased significantly,but decreased in the late stage of decomposition.The organic carbon content of cotton stalk treated with low nitrogen(N_(1)and N_(2))was the highest.There was no significant difference in total nitrogen content between treatments.Nitrogen addition treatment significantly reduced the pH value and salinity of soil;Soil organic carbon content was negatively correlated with lignin and hemicellulosic content of cotton stalks(P<0.05,P<0.01).【Conclusion】Returning straw to the field and applying nitrogen fertilizer can accelerate the decomposition of cotton straw,while the low-nitrogen treatment(N_(1)and N_(2))can not only accelerate the degradation of straw,but also increase the content of soil organic carbon,so as to fertilize the soil.
作者
梁萌
王志方
马健
李晨华
LIANG Meng;WANG Zhifang;MA Jian;LI Chenhua(State Key laboratory of Desert and Oasis Ecology,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,China;Fukang National Station of Desert Ecosystem Observation and Research,Chinese Academy of Sciences,Fukang Xinjiang 831505,China;University of Chinese Academy of Science,Beijing 100049,China;Xinjiang Special Environmental Microbiology Laboratory/Research Institute of Applied Microbiology,Xinjiang Academy of Agricultural Sciences,Urumqi 830091,China)
出处
《新疆农业科学》
CAS
CSCD
北大核心
2021年第8期1427-1434,共8页
Xinjiang Agricultural Sciences
基金
新疆维吾尔自治区自然科学基金(2019D01A97)
国家自然科学基金(41671114)。
关键词
棉秆腐解
氮肥
土壤理化性质
cotton stalk decomposition
nitrogen fertilizer
physical and chemical properties of soil